1. Pediatric Hematology and Oncology; University Children's Hospital Muenster; Muenster Germany
2. Department of Pediatrics; University Medical Center Schleswig-Holstein; Campus Kiel Kiel Germany
3. Department of Pediatric Oncology/Hematology; Charité Universitätsmedizin Berlin; Berlin Germany
4. Pediatric Hematology and Oncology; Hannover Medical High School; Hannover Germany
5. Department of Pediatric Hematology and Oncology; Justus-Liebig-University; Giessen Germany
6. St. Anna Children's Cancer Research Institute; Department of Pediatrics; Medical University School; Vienna Austria
7. St. Anna Children's Hospital; Department of Pediatrics; Medical University School; Vienna Austria
8. Department of Paediatrics; Martin-Luther University of Halle-Wittenberg; Halle Germany
9. Klinikum Stuttgart-Olgahospital; Pediatrics 5 (Oncology, Hematology, Immunology; General Pediatrics, Gastroenterology, Rheumatology); Stuttgart Germany
10. Department of Pediatric Oncology and Hematology; Children's Hospital; University of Cologne; Cologne Germany
11. Pediatric Oncology; University Hospital of Saarland; Homburg/Saar Germany
12. Department of Pediatric Hematology and Oncology; University Medical Center Hamburg-Eppendorf; Hamburg Germany
13. German Childhood Cancer Registry at Institute for Medical Biostatistics, Epidemiology and Informatics; University Medical Center of Johannes Gutenberg-University; Mainz Germany